MErging the Interface: Power, area and accuracy co-optimization for RRAM crossbar-based mixed-signal computing system

The invention of resistive-switching random access memory (RRAM) devices and RRAM crossbar-based computing system (RCS) demonstrate a promising solution for better performance and power efficiency. The interfaces between analog and digital units, especially AD/DAs, take up most of the area and power consumption of RCS and are always the bottleneck of mixed-signal computing systems. In this work, we propose a novel architecture, MEI, to minimize the overhead of AD/DA by MErging the Interface into the RRAM cross-bar. An optional ensemble method, the Serial Array Adaptive Boosting (SAAB), is also introduced to take advantage of the area and power saved by MEI and boost the accuracy and robustness of RCS. On top of these two methods, a design space exploration is proposed to achieve trade-offs among accuracy, area, and power consumption. Experimental results on 6 diverse benchmarks demonstrate that, compared with the traditional architecture with AD/DAs, MEI is able to save 54.63%~86.14% area and reduce 61.82%~86.80% power consumption under quality guarantees; and SAAB can further improve the accuracy by 5.76% on average and ensure the system performance under noisy conditions.